1. Field of the Invention
The present invention relates to detection systems, and more particularly, to a detection system for detecting a moving object crossing a border.
2. Description of the Related Art
A conventional position correction device with alarm is disclosed by U.S. Pat. No. 7,920,066, wherein the border coordinates of a detection area is saved in a monitoring device thereof. A positioning device is worn on an animal to-be-monitored. By use of GPS, positions of the animals wearing the positioning device are detected, such that when the animal moves close to the predetermined border, an alarm is triggered.
However, the monitoring area and border abovementioned are fixed. In other words, the monitoring function is only carried out upon a fixed area. Therefore, such monitoring device is not applicable to objects on a moving carrier. For example, when the moving carrier refers to an ocean liner which continuously moves, the to-be-monitored area is not fixed. As a result, such monitoring device fails to be applied to a person on the ocean liner for detecting the person crossing a border and falling into the ocean.
Further, for detecting person accidentally falling into the ocean, TW200849152 discloses a rescue system for sailor, wherein a plurality of transmitter are disposed around a ship, and the detection area of each transmitter does not overlap. Also, each person wears a sensor, such that the sensor receives the position signal of the transmitter. When the sensor determines that a person falls into the ocean, the position signal last received is transmitted to the receiver, and the receiver sends out an alarm.
However, the receiver is only capable of knowing the last position of the transmitter, failing to know the correct falling position of the person. Also, the receiver of the monitoring end of the device only passively monitors the sensor. In other words, the receiver is unable to actively detect if the sensor is out of the range of the ship and immediately send out the alarm. Therefore, such device fails to achieve an accurately monitoring function.